As a human being, have you ever wondered when humans colonized the Americas? Where did anatomically modern humans migrate from? What routes did humans use?

In an effort to answer these questions, Benjamin Auerbach, assistant professor of anthropology, spoke to the UT Science Forum about the process and history of human migration from an archeological standpoint.
We are looking at the end of the story. We want to understand the beginning of the story. -Benjamin Auerbach, assistant professor of anthropology

The story starts with the two earliest archaeological locations in North America which trace back to 14,000 years ago. These sites are located at Swan Point in Alaska and Monte Verde in Chile. Note that Swan Point sits at the top of North America and Monte Verde sits at the bottom of South America. Such a distance between two sites of such similar age and archaeology calls for an explanation.

Auerbach suggests that humans traveled from Asia to Alaska. Subsequently, some humans made the migration south to Chile.

To understand human development, we need to go back a bit further in time. Auerbach proposes the "Beringian Standstill" theory. This hypothesizes that a group of humans were living in Asia, then a smaller group of humans branched off from the original group. This new group resided in Berinigia, the area between Alaska and Asia, and developed mutations as a result of selective pressures. Then, the new group traveled to the Americas.

Auerbach notes that these mutations were a result of selective pressure due to the colder environment. The group of humans that branched off developed physical characteristics that were necessary for survival.
 
This change can even be recognized today. Europeans typically have wider bodies than Africans. Wider bodies allow for more body fat. In comparison, Africans have slimmer bodies because they do not need excess body fat to stay warm.

According to Auerbach, the "Beringian Standstill" theory receives validation by tracing ancestry through mtDNA (mitochondrial DNA). Archaeologists discovered five clusters of genes of mutations that linked a common ancestry to the humans of the Americas. The same five cluster group in North and South America appear in the area of Asia near Alaska, thus supporting the Asia to Alaska migration theory.

With this information, we can answer our original questions and hopefully many more.